Telephone-exchange system.



C. W. KECKLER.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED MAY 11. 1918.

1,302,809. Patented May 6, 1919..

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CHARLES W. KECKLER, OF NEWARK, JERSEY, ASSIGNOR T0 WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y. A CORPORATION OF NEW YORK.

TELEPHONE-EXGHAN GE SYSTEM.

\ Specification of Letters Patent.

llatented May 6, 1919.

Application filed May 11, 1918. Serial No. 233,920.

To all whom it may concern:

Be it known that I, CHARLES W. KEGKLER, a citizen of the United States,residing at Newark, in the county of Essex, State of New Jersey, have invented certain new and useful Improvements in Telephone-Exchange Systems, of which the following is a full, clear, concise, and exactdescription.

This invention relates to telephone exchange systems and more particularly to those in which plugs associated with connecting or link .circuits cooperate with jack terminals of the line circuits.

In systems of this character it is desirable to expedite as much as may be possible, the handling of connections and with this object in view many features have been introduced in the past whereby certain individual operations previously required have been eliminated, thus efliecting a saving of the operators time and consequently materially increasing the efficiency of the exchange system.

It is particularly desirable to minimize the time required by the operator in effecting the disconnection of the link or connect ing circuit from the line circuit upon the com letion of the conversation over an esta lished connection. Notonly is the operator thereby enabled to devote more time to answering calls and establishing connec tionsbut the engaged circuits are also released more quickly for other service.

It is the object of the present invention to provide a simple and inexpensive arrangement whereby someof the individual operations are eliminated and thetime required by the operator in handling disconnections is thereby materially reduced.

To attain this object, in accordance with a feature of the invention, a plug ejecting device associated with a jack of the line circuit is controlled by means associated with the line and connecting circuits c06perat-- ing to partially complete the operating cir cuit of the ejecting device upon the connection of the connecting circuit with the line and thereafter to transfer the control of the ejecting device to thesubscribers station on the associated line circuit.

This and other features, not specifically mentioned above, will more clearly appear from the following specification and the an- .nexed drawing in which are shown aline circuit equipped with an ejecting device, and sufiicient portions of a connecting or link circuit to properly illustrate the invention, In the accompanying. drawing, an ordinary line circuit A equipped with the usual line and cutoff relays 1 and 3, respectively, and the line signal 2, terminates in a jack (Band is provided with a plug ejecting device 12 which may be ofany suitable type. Relays 4 and 5, associated with the cutoff relay 3, cooperate with controlling relays 8 and 9 and resistance 10 of the link or connecting circuit 13 to control the operation of the ejectingdevice. The connecting circuit; B may beof any usual type, only sufiicient portions thereof being shown to illustrate the ,applicationin the present case. It is thoughtthat the invention will be more fully comprehended from the following description of the operation of the system. o l

Assuming that a call is initiated by a subscriber associated withline A, the line relay I operates and lights the calling lamp 2 in the usual manner. In answering the call, the plug '7 of the connecting or link circuit B is inserted in jack 6, thereby operating relay 8 over a circuit established from battery through the lower winding of relay 8, the ring contacts of plug 7 and of jack 6, over one line conductor, the switchhook contacts and associated apparatus of the station connected therewith, over the other line conductor, thetip contacts of jacli 6 and plug 7 and the upper winding of relay 8 to ground. A second circuit is thereupon established from battery through the alternate contact of relay 8, the winding of relay 9, the sleeve contacts of plug 7 and jack 6, the winding of marginal relay 4 andthe winding of relay 3 to ground. The cutofi' relay 3 operates, disconnecting the line relay 1 from the line conductors and extinguishing the line lamp 2 in the usual manner. Relay 9 also operates, but, due to the operation of relay 8, the supervisory lamp 11 is not lighted. Marginal relay t operates, establishing a, circuit from battery through the winding of relay 5 and the alternate contact of relay 4 to ground. Relay 5 thereupon operates and completes a locking circuit therefor, extending from battery through the winding and the left-hand contact of relay 5 and the right-hand contact of relay 3 to ground.

Upon the restoration of the receiver at the station A, relay 8 is released by the opening of'its operatingcircuit. A circuit is thereupon completed for lamp 11 extending from battery through the lower contact of relay 8, the contact of relay 9 and lamp 11 to ground. However, the lamp 11 does not light due to the simultaneous operation of the plug ejecting device 12. The operation of relay 8 also removes the shunt previously established around resistance 10, thereby including such resistance in series with the windings of relays 3, i and 9. Therefore, the resistance of such circuit is increased to such an extent that marginal relay 4: releases, opening the operating circuit of relay 5 and completing a circuitfrom battery through the winding of the ejecting device 12, the right-hand contact of relay 5 and the normal contactof relay 4 to; ground.

The consequent energization of the winding of the ejecting device 12 causes the solenoid thereof to be drawn into the device with suflicient force to expel the plug 7 from the jack 6. Thereupon all apparatus returns to the normal condition shown on the drawing.

In case plug 7 is inserted in jack 6 of :1 called line A, a circuit is established from battery through resistance 10, winding of relay 9, the sleeve contacts of plug 7 and jack 6, the winding of marginal relay 4 and the winding of relay 3 to ground. Relay 3- operates as previously described, removing the line relay from its-association with the line circuit and preventing the lighting of the line lamp 2.

Relay 9 also operates, lighting lamp 11 over a circuit established from battery through. the normal contact of relay 8, the contact of relay 9 and the lamp 11 to ground. However, marginal relay l receives an insufficient amount of current to cause its operation. When the called station answers, relay 8 operates over the circuit previously traced therefor. The supervisory lamp 11 is thereupon extinguished due to the opening of the circuit therefor, at the normal contact of relay '8. The operation of relay 8 also. establishes a shunt around resistance 10, thereby sufiiciently reducing the re sistance of the circuit including marginal relay 4, to permit the operation of such relay. The conditionsare now the same as those existing after the operators answer of the incoming call as described in the previous case, and the subsequent operations of the system agree with those described in that connection.

It will thus be evident that the operation of the ejecting device is entirely within the control of the subscri-bers station after connection has been established with the associatedline. With such an arrangement the terminating in a plug for connection with.

the jack, a plug ejecting device associated with the jack controlled by variations in the resistance of the sleeve circuit of the connected'line and link circuits, and subscriber controlled means adapted to cause such variations in resistance.

2. In a telephone exchange system, a line circuitterminating in a jack, a link circuit terminating in a plug for connection with the jack, a plug ejecting device associated with the ack, a relay .operable upon the insertion of the plug in the jack of a calling line to partially prepare a circuit for the device, and means controlled by the calling subscriber releasing the relay to complete the circuit of the device to causethe operation thereof.

3. In a telephone exchange system, a line circuit terminating in a jack, a link circuit terminating in a plug for connection with the jack, a plug ejecting device associated with the jack, a sleeve relay controlling the device and controlled by variations in the re sistance of the sleeve circuit of the connected line and link circuits, and means controlled by the restoration of the receiver at the called station to release the relay thereby closing the circuit of and operating the ejecting device.

4. In a telephone exchange system, a line circuit terminating in a jack, a link circuit terminating in a plug for connection with the jack, a plug ejecting device associated with the jack, a sleeve relay associated with the line circuit adapted to maintain the ejecting device ineffective while thereceiver of the associated station is absent from its switchhook and the link circuit is connected with the line circuit, and means adapted to vary the currentfiow through the relay upon the restoration of the receiver to the switch hook thereby releasing the relay and rendering the ejecting device effective. 7

5. In a telephone exchange system, a line circuit terminating in a jack, a link circuit terminating in "a plug for connection with the jack, a plug ejecting device associated with the jack, .a relay associated with a called line adapted to remain inert upon the connection of the link circuit with the line, a resistance, and means operating uponthe closing of the called line to operate the relay, and upon the opening of the called line to include the resistance in circuit with the relay to cause its release and the operation of the ejecting device.

6. In a telephone exchange system, a line circuit terminating. in a jack, 9. link circuit terminating in a plug for connection with the jack, a plug ejecting device controlled by variations in current flow in the sleeve circuit of the engaged line and link circuits caused by the operation of the switchhook at the associated station.

7. In a telephone exchange system, a line circuit terminating in a jack, a link circuit terminating in a plug for connection With the jack, a plug ejecting device associated with the jack, and a plurality of relays co operating in one manner to render the ejecting device ineffective upon the insertion of the plug in the jack of a called line, cooperating in a second manner upon the answer of the called station to maintain the ejecting device ineffective and cooperating in a third manner upon the subsequent restoration of the receiver to the switchhook at the called station to render the ejecting device efi'ective.

8. In a telephone exchange system, a line circuit terminating in a jack, a link circuit terminating in a plug for connection with the j ack, a plug ejecting device associated With the jack, a locking relay, a marginal relay controlling the operating circuit thereof and cooperating therewith to control the operation of the ejecting device, and a bridged relay controlling the operation of the marginal relay.

In Witness whereof, I hereunto subscribe my name this 7th day of May A. D., 1918.

CHARLES W. KEOKLER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

